21.15.7.1 Arguments

uncertainty

Specifies the time in nanoseconds that represents the amount of variation between two clock edges. The value must be a positive floating point number.

-from

Specifies that the clock-to-clock uncertainty applies to both rising and falling edges of the source clock list. You can specify only one of the -from, -rise_from, or -fall_from arguments for the constraint to be valid. This option is the default.

-rise_from

Specifies that the clock-to-clock uncertainty applies only to rising edges of the source clock list. You can specify only one of the -from, -rise_from, or -fall_from arguments for the constraint to be valid.

-fall_from

Specifies that the clock-to-clock uncertainty applies only to falling edges of the source clock list. You can specify only one of the -from, -rise_from, or -fall_from arguments for the constraint to be valid.

from_clock_list

Specifies the list of clock names as the uncertainty source.

-to

Specifies that the clock-to-clock uncertainty applies to both rising and falling edges of the destination clock list. You can specify only one of the -to, -rise_to , or -fall_to arguments for the constraint to be valid.

-rise_to

Specifies that the clock-to-clock uncertainty applies only to rising edges of the destination clock list. You can specify only one of the -to, -rise_to , or -fall_to arguments for the constraint to be valid.

-fall_to

Specifies that the clock-to-clock uncertainty applies only to falling edges of the destination clock list. You can specify only one of the -to, -rise_to , or -fall_to arguments for the constraint to be valid.

to_clock_list

Specifies the list of clock names as the uncertainty destination.

-setup

Specifies that the uncertainty applies only to setup checks. If you do not specify either option (-setup or -hold ) or if you specify both options, the uncertainty applies to both setup and hold checks.

-hold

Specifies that the uncertainty applies only to hold checks. If you do not specify either option (-setup or -hold ) or if you specify both options, the uncertainty applies to both setup and hold checks.